With Samsung (and ALL of the other manufacturers) they have never had a backdoor on any of the phones, at least since Android 6, maybe 5. There was a way prior with the Google account, but it's been unsupported for years at this point. The reason it was dropped without hesitation is because the FBI picked a fight with Apple (and lost). The problem was keeping it sets a dangerous precedent, so it was removed and support was abandoned in the blink of an eye. The reason is if the manufacturer/SW developer cannot get in, then they can legally tell the FBI to pound sand. Ever since that case went down, everyone uses non-reversible encryption because the fight that the FBI tried to put up served as a warning.
That said, it may still be possible with 3rd party SW on a non-encrypted phone, but a lot of phones use the passcode AS the key, or an inaccessible private key (you and the manufacturer)+passcode encryption. A lot of the phones released since the FBI didn't get their permanently encrypt themselves during setup, and push a passcode which also acts as encryption. The last phone I had with reversible encryption was the LG G4.
I do feel bad how it affects people like you, but I do not want my phone to be backdoored by anyone, even the manufacturer. It's a dangerous precedent since the FBI tried to compel Apple in 2015. Apple dropped the backdoor in iOS 8 and uses the passcode as encryption as well.